(A) Diffraction of light by atmosphere
(B) Scattering of light by atmosphere
(C) Reflection of light by atmosphere
(D) Refraction of light by atmosphere
Which one of the following is used to restore the colour of old oil paintings?
(A) Sodium peroxide
(B) Barium peroxide
(C) Hydrogen peroxide
(D) Ozone
Which of the following compounds is commonly used as an antiseptic in mouthwashes and toothpastes?
(A) Sodium chloride
(B) Hydrogen peroxide
(C) Saltpetre
(D) Borax
Which of the following is a not metal that remains liquid at room temperature?
(A) Phosphorous
(B) Chlorine
(C) Helium
(D) Bromine
Which of the following is chiefly present in LPG?
(A) Propane
(B) Ethane
(C) Butane
(D) Methane
Which of the following is used to remove rust stains on cloth?
(A) Oxalic acid solution
(B) Lime
(C) Petrol
(D) Kerosene
First metal used by a man was?
(A) Brass
(B) Bronze
(C) Silver
(D) Copper
Metals are good conductors because?
(A) They contain reflecting surface
(B) They contain free electrons
(C) The molecules in them collide very freely
(D) None of the above